Synthesize ctrl-wheel events on touchpad pinch

content/browser/renderer_host/input/input_router_impl.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_
 
 #include <queue>
 
 #include "base/basictypes.h"
@@ skipping 100 matching lines @@
   // Returns true if |input_event| was consumed by the client.
   bool OfferToClient(const blink::WebInputEvent& input_event,
                      const ui::LatencyInfo& latency_info);
 
   // Returns true if |input_event| was successfully sent to the renderer
   // as an async IPC Message.
   bool OfferToRenderer(const blink::WebInputEvent& input_event,
                        const ui::LatencyInfo& latency_info,
                        bool is_keyboard_shortcut);
 
+  // A data structure that attaches some metadata to a WebMouseWheelEvent
+  // and its latency info.
+  struct QueuedWheelEvent {
+    QueuedWheelEvent();
+    QueuedWheelEvent(const MouseWheelEventWithLatencyInfo& event,
+                     bool synthesized_from_pinch);
+    ~QueuedWheelEvent();
+
+    MouseWheelEventWithLatencyInfo event;
+    bool synthesized_from_pinch;
+  };
+
+  // Enqueue or send a mouse wheel event.
+  void SendWheelEvent(const QueuedWheelEvent& wheel_event);
+
+  // Given a Touchpad GesturePinchUpdate event, create and send a synthetic
+  // wheel event for it.
+  void SendSyntheticWheelEventForPinch(
+      const GestureEventWithLatencyInfo& pinch_event);
+
   // IPC message handlers
   void OnInputEventAck(blink::WebInputEvent::Type event_type,
                        InputEventAckState ack_result,
                        const ui::LatencyInfo& latency_info);
   void OnMsgMoveCaretAck();
   void OnSelectRangeAck();
   void OnHasTouchEventHandlers(bool has_handlers);
   void OnSetTouchAction(TouchAction touch_action);
 
   // Indicates the source of an ack provided to |ProcessInputEventAck()|.
@@ skipping 78 matching lines @@
   // for a corresponding InputHostMsg_HandleInputEvent_ACK message.
   bool mouse_move_pending_;
 
   // The next mouse move event to send (only non-null while mouse_move_pending_
   // is true).
   scoped_ptr<MouseEventWithLatencyInfo> next_mouse_move_;
 
   // (Similar to |mouse_move_pending_|.) True if a mouse wheel event was sent
   // and we are waiting for a corresponding ack.
   bool mouse_wheel_pending_;
-  MouseWheelEventWithLatencyInfo current_wheel_event_;
+  QueuedWheelEvent current_wheel_event_;
 
   // (Similar to |next_mouse_move_|.) The next mouse wheel events to send.
   // Unlike mouse moves, mouse wheel events received while one is pending are
   // coalesced (by accumulating deltas) if they match the previous event in
   // modifiers. On the Mac, in particular, mouse wheel events are received at a
   // high rate; not waiting for the ack results in jankiness, and using the same
   // mechanism as for mouse moves (just dropping old events when multiple ones
   // would be queued) results in very slow scrolling.
-  typedef std::deque<MouseWheelEventWithLatencyInfo> WheelEventQueue;
+  typedef std::deque<QueuedWheelEvent> WheelEventQueue;
   WheelEventQueue coalesced_mouse_wheel_events_;
 
   // A queue of keyboard events. We can't trust data from the renderer so we
   // stuff key events into a queue and pop them out on ACK, feeding our copy
   // back to whatever unhandled handler instead of the returned version.
   typedef std::deque<NativeWebKeyboardEvent> KeyQueue;
   KeyQueue key_queue_;
 
   // The time when an input event was sent to the client.
   base::TimeTicks input_event_start_time_;
@@ skipping 17 matching lines @@
   GestureEventQueue gesture_event_queue_;
   TouchActionFilter touch_action_filter_;
   InputEventStreamValidator event_stream_validator_;
 
   DISALLOW_COPY_AND_ASSIGN(InputRouterImpl);
 };
 
 }  // namespace content
 
 #endif // CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_